gminor asks about "as you think, so shall you be"

I'm not sure which forum I need to be in to ask this, so I'll try it here. Dr. Dyer often uses the phrase "as you think, so shall you be". I was thinking this was a Bible verse but I haven't found it. I must be mistaken Does anyone know the origin of this phrase?

Thanks,
George

Solomon said "For as he thinketh in his heart, so is he" (Proverbs 237)

Thanks for your answer. I don't think I would have ever found that.